Driver Speed vs. Crash Risk: Pilot Study Summary (TTI-1998-3)

This report summarizes the development and pilot test of an automated data collection system that utilizes Global Positioning System (GPS) technology to continuously measure individual driver speed. With little previous research having been carried out on the measurement of normal individual driver behavior, the propensity to speed, and the relationship of these two factors on crash risk, it is hard to determine whether or not people who might be categorized as "speeders" are actually at greater risk of crash involvement. The National Highway Traffic Safety Administration sponsored this pilot study in an effort to advance the understanding of the relationship between the speeds at which motorists drive and crash probability. The resulting approach offers a unique microscopic view of individual driving behavior, and a source of accurate pre-crash travel speed information. Ultimately, this approach could be used on a larger sample to determine the crash risk relationship for various sub-populations and help to identify potential countermeasures for these groups.|For this pilot study, 50 vehicles were equipped with advanced vehicle tracking devices which facilitated the continuous monitoring and logging of speed and location data for a period of four months. While this sample of participants was not large enough to draw statistically significant conclusions about the relationship between speed and crash risk, it did provide for a proof-of-concept of the technology and a potential approach for quantifying the relationship in a full-scale study. This report will provide findings on: I)proof-of-concept of technology for this application; 2) liability issues involved in obtaining vehicle tracking information; 3) effectiveness of various data acquisition rates; 4) elements of the relationship between driver behavior and the roadway environment; 5) issues associated with tracking crashes; and 6) recommendations for a full-scale study.